In recent years, substrate processing apparatuses have been used to perform various kinds of processing for substrates such as semiconductor wafers. As one example of the substrate processing apparatus, a CMP (Chemical Mechanical Polishing) apparatus for performing polishing processing of substrates is cited.
A CMP apparatus includes a polishing unit for performing polishing processing of a substrate, a cleaning unit for performing cleaning processing and drying processing of a substrate, a load/unload unit that delivers a substrate to the polishing unit and receives a substrate for which the cleaning processing and the drying processing are performed by the cleaning unit, and the like. Further, the CMP apparatus includes a transfer unit that performs transfer of substrates in the polishing unit, the cleaning unit and the load/unload unit. The CMP apparatus sequentially performs various kinds of processing of polishing, cleaning and drying while transferring substrates by the transfer unit.
Incidentally, it is known that the transfer unit performs transfer for optimizing substrate processing efficiency when the polishing unit includes a plurality of polishing sections, and the cleaning unit includes a plurality of cleaning sections. That is to say, when the transfer unit transfers a substrate to the polishing unit from the load/unload unit, the transfer unit transfers the substrate to a polishing section that can perform polishing processing for the substrate the soonest among the plurality of polishing sections. Further, when the transfer unit transfers a substrate to the cleaning unit from the polishing unit, the transfer unit transfers the substrate to the cleaning section that can perform cleaning processing for the substrate the soonest among the plurality of cleaning sections.
Here, when some of the plurality of polishing sections, or some of the plurality of cleaning sections cannot be used due to maintenance or the like, the transfer unit transfers the substrate to the polishing section or the cleaning section which is not under maintenance. Further, when maintenance of the polishing section or the cleaning section is ended, the transfer unit transfers a test substrate which is different from a substrate for production to the polishing section or the cleaning section the maintenance of which is finished, in order to examine whether or not the polishing section or the cleaning section the maintenance of which is finished operates normally.